Fix: Gunicorn process detection (#208)

* Check proc cmdline for gunicorn process

* Change Strategy to avoid circular import

* Remove debug print statements

* Python 2.7 compatibility

Author: pglombardo

instana/__init__.py

@@ -85,6 +85,7 @@ def boot_agent():
     # Hooks
     from .hooks import hook_uwsgi
 
+
 if "INSTANA_MAGIC" in os.environ:
     pkg_resources.working_set.add_entry("/tmp/instana/python")
 

instana/log.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 import logging
 import os
 import sys
@@ -35,22 +36,36 @@ def running_in_gunicorn():
     process_check = False
     package_check = False
 
-    if hasattr(sys, 'argv'):
-        for arg in sys.argv:
-            if arg.find('gunicorn') >= 0:
+    try:
+        # Is this a gunicorn process?
+        if hasattr(sys, 'argv'):
+            for arg in sys.argv:
+                if arg.find('gunicorn') >= 0:
+                    process_check = True
+        elif os.path.isfile("/proc/self/cmdline"):
+            with open("/proc/self/cmdline") as cmd:
+                contents = cmd.read()
+
+            parts = contents.split('\0')
+            parts.pop()
+            cmdline = " ".join(parts)
+
+            if cmdline.find('gunicorn') >= 0:
                 process_check = True
-    else:
-        # We have no command line so rely on the gunicorn package presence entirely
-        process_check = True
 
-    try:
-        from gunicorn import glogging
-    except ImportError:
-        pass
-    else:
-        package_check = True
+        # Is the glogging package available?
+        try:
+            from gunicorn import glogging
+        except ImportError:
+            pass
+        else:
+            package_check = True
 
-    return process_check and package_check
+        # Both have to be true for gunicorn logging
+        return process_check and package_check
+    except Exception as e:
+        print("Instana.log.running_in_gunicorn: %s", e, file=sys.stderr)
+        return False
 
 
 if running_in_gunicorn():

instana/meter.py

@@ -12,7 +12,7 @@
 from pkg_resources import DistributionNotFound, get_distribution
 
 from .log import logger
-from .util import get_py_source, package_version, every
+from .util import get_py_source, package_version, every, get_proc_cmdline
 
 
 class Snapshot(object):
@@ -241,33 +241,6 @@ def handle_agent_tasks(self, task):
 
         self.agent.task_response(task["messageId"], payload)
 
-    def get_proc_cmdline(self, as_string=False):
-        """
-        Parse the proc file system for the command line of this process.  If not available, then return a default.
-        Return is dependent on the value of `as_string`.  If True, return the full command line as a string,
-        otherwise a list.
-        """
-        name = "python"
-        if os.path.isfile("/proc/self/cmdline"):
-            with open("/proc/self/cmdline") as cmd:
-                name = cmd.read()
-        else:
-            # Most likely not on a *nix based OS.  Return a default
-            if as_string is True:
-                return name
-            else:
-                return [name]
-
-        # /proc/self/command line will have strings with null bytes such as "/usr/bin/python\0-s\0-d\0".  This
-        # bit will prep the return value and drop the trailing null byte
-        parts = name.split('\0')
-        parts.pop()
-
-        if as_string is True:
-            parts = " ".join(parts)
-
-        return parts
-
     def get_application_name(self):
         """ This function makes a best effort to name this application process. """
 
@@ -281,15 +254,15 @@ def get_application_name(self):
             app_name = "python" # the default name
 
             if not hasattr(sys, 'argv'):
-                proc_cmdline = self.get_proc_cmdline(as_string=False)
+                proc_cmdline = get_proc_cmdline(as_string=False)
                 return os.path.basename(proc_cmdline[0])
 
             basename = os.path.basename(sys.argv[0])
             if basename == "gunicorn":
                 # gunicorn renames their processes to pretty things - we use those by default
                 # gunicorn: master [djface.wsgi]
                 # gunicorn: worker [djface.wsgi]
-                app_name = self.get_proc_cmdline(as_string=True)
+                app_name = get_proc_cmdline(as_string=True)
 
                 if app_name is None:
                     app_name = basename

instana/util.py

@@ -93,6 +93,34 @@ def extractor(o):
         logger.debug("to_json non-fatal encoding issue: ", exc_info=True)
 
 
+def get_proc_cmdline(as_string=False):
+    """
+    Parse the proc file system for the command line of this process.  If not available, then return a default.
+    Return is dependent on the value of `as_string`.  If True, return the full command line as a string,
+    otherwise a list.
+    """
+    name = "python"
+    if os.path.isfile("/proc/self/cmdline"):
+        with open("/proc/self/cmdline") as cmd:
+            name = cmd.read()
+    else:
+        # Most likely not on a *nix based OS.  Return a default
+        if as_string is True:
+            return name
+        else:
+            return [name]
+
+    # /proc/self/command line will have strings with null bytes such as "/usr/bin/python\0-s\0-d\0".  This
+    # bit will prep the return value and drop the trailing null byte
+    parts = name.split('\0')
+    parts.pop()
+
+    if as_string is True:
+        parts = " ".join(parts)
+
+    return parts
+
+
 def package_version():
     """
     Determine the version of this package.
@@ -234,13 +262,12 @@ def get_py_source(file):
 
     @param file [String] The fully qualified path to a file
     """
+    response = None
     try:
-        response = None
-        pysource = ""
-
         if regexp_py.search(file) is None:
             response = {"error": "Only Python source files are allowed. (*.py)"}
         else:
+            pysource = ""
             with open(file, 'r') as pyfile:
                 pysource = pyfile.read()
 
@@ -251,6 +278,7 @@ def get_py_source(file):
     finally:
         return response
 
+
 # Used by get_py_source
 regexp_py = re.compile('\.py$')
 

tests/test_secrets.py

@@ -2,7 +2,6 @@
 
 import unittest
 
-from instana.singletons import agent
 from instana.util import strip_secrets